Stripper for the drawing frames of spinning machines

ABSTRACT

A leather-covered stripper roller, bearing upon one of two coacting transport rollers for the conveyance of filamentary material to remove adhering lint or fluff with the aid of an associated suction device, comprises a tube rotatably journaled on a fixed shaft which carries an externally operable brake engageable with the tube from within. The brake preferably includes an elastically expandable sleeve which is intermittently inflatable by compressed air to arrest the stripper roller against frictional entrainment by the engaged transport roller.

United States Patent Muller et a1.

[54] STRIPPER FOR THE DRAWING FRAMES OF SPINNING MACHINES [72] inventors: Adolf M. Muller, Waxensteinstr 67; Josef Grosselfinger, Schillstr. 186, both of Augsburg, Germany 221 Filed: May 25,1970 211 Appl. Na; 40,129

[30] Foreign Application Priority Data May 23, 1969 Germany P 19 26 419.8

[52] U.S.Cl.' ..l9/263 [51] Int. Cl. ..D0lh 5/62 [58] Field of Search ..l9/245. 263, 264, 265;

[56] References Cited UNITED STATES PATENTS 3,408,698 11/1968 Rosele et al. .....19/263 [451 Dec. 12,1972

FOREIGN PATENTS OR APPLlCATlONS 609,142 2/1935 Germany ..l9/264 965,414 7/1964 Great Britain ..l9/264 Primary Examiner-Dorsey Newton Attorney-Karl F. Ross [57] ABSTRACT A leather-covered stripper roller, bearing upon one of two coacting transport rollers for the conveyance of filamentary material to remove adhering lint or fluff with the aid of an associated suction device, comprises a tube rotatably journaled on a fixed shaft which carries an externally operable brake engageable with the tube from withinJThe brake preferably includes an elastically expandable sleeve which is intermittently inflatable by compressed air to arrest the stripper roller against frictional entrainment by the engaged transport roller.

6 Claims, 3 Drawing Figures PKTE'N'TED DE 12 1912 PRESSURE FLUID INVNTOR s: ADOLF I'LARTIN MULLLR JOQQF GROSSLLFINGEJR for the drawing frames of spinning machines, in whichthe rotational movement of a stripping roller contacting at least one of the grooved rolls in the drawing frame is intermittently retarded or stopped.

It is known to .surround the stripping rollers at least partially with a suction trough of a suction device, so that fluff removed from the stripping roller and the grooved rolls, adhering to the surface of the stripping roller, may be sucked off as the stripping roller rotates. It has been found, however, that strippingrollers rotating at a constant speed fail to clean sufficiently effectively and for this reason it hasbecome the practice to maintain the stripping roller at a lower peripheral speed than its associated roller in the drawing frame. v V

- It is, however, also known to drive the stripping roller intermittently so that,when a stripping roller is stationary or rotates only slightly, a considerable friction is produced on the surfaceof the drawing roller, resulting in the removal of the flock meanwhile collected.

In one of suchknown clearers orstrippers, a brake in the form of a resilient clamp guided in a groove provided in the stripping roller is used as the means by which the stripping roller is stopped. At the same location, the associated grooved roller is provided with a cam for the purpose of releasing the brake for a short period during each revolution of the grooved roller (German Patent Specification No. 1,253,618). A periodic stopping vand rotation of the stripping roller, whose rotational movement is produced by friction with the grooved roller, is thereby attained.

It appears to be doubtful whether this known method canproduce the desired results at all, since, particularly at high conveying speeds, considerable dynamic forces generated, on the one hand, by the eccentric masses and, on the other hand, by impacts of the cam striking in rapid succession against the braking elements act upon the grooved roller and upon the stripping roller. Apart from these effects, the stripping roller has to be of a stepped construction and the braking elements have to be provided at the locations where flock and other dirt collect.

Tests have also shown that no adequate results can be obtained with the known clearers or strippers when specific material, particularly synthetic thread or thread of cellulose wool or of a poor-quality cotton, is spun. The known clearershave an inadequate durability in practical operation and thus fall out or fail quickly, quite apart from the fact that they fulfill their purpose inadequately by reason of severe lint formation and soiling of the external braking elements.

It is an object of the invention to avoid the disadvantages of the known clearers or strippers and to provide apparatus by which the stripping roller is intermittently stopped, in which no flock can settle, and which enables sudden transitions from standstill to rotation and vice versa without requiring considerable expenditure. It is a further object of the invention to keep the braking of the stripping roller free from vibration.

lnaccordance with the invention, these objects are achieved in that a tubular stripping roller mounted on a rigid shaft is connectable to a brake provided in the in- The mounting of the brake in the interior of the stripping roller affords the decisive advantage that flock or other dirt is unable to settle in the zone of the brake. Moreover, the surfacesof the stripping roller and of its associated roller in the drawing frame need not be provided with a special profile as is necessary in the present state of the art, the generation of dynamic out-of-balance forces being thus prevented by this improvement.

The brake according to the inventionmay be of various constructions. Thus, for example, permanent magnets, magneto-couplings, braking laminae, or other eleproduced during the pressure phase.

5 terior of the tube and preferably supported by the shaft. 6

The stripping roller is advantageously at least partially enclosed by a suction device of known construction.

In accordance with amore particular feature of our invention, the brake may be a hollow cylinder having an elastically deformable, and thus expandable, wall extending along at least part of the inner surface of the tubular stripping roller. It will be understood that, instead of introducing a pressure medium, the elastic wall may be deformed by mechanical means, for example by subjecting a cylindrical hose made of an elastic materialto an axial load whereby the zone in the middle of the cylinder is caused to bulge out and thus to bear with braking action against the inner surface of the stripping roller.

However, when the brake according to the invention is exposed to a fluid under pressure, for example compressed air, guide members mounted in spaced-apart relationship on the shaft of the stripping roller are advantageously provided in engagement with the elastic jacket; a cylindrical spacer, whose outer surface is located at a short radial distance from the elastic jacket, is disposed between the guide members, and has a radial bore for the passage of the pressure medium. At least one end face of the stripping roller may be provided with a bore for the supply of pressure medium and with a connecting fitting.

Tests have shown that the brake according to the invention can be caused to bulge out by a short-time pressure impulse, and its elastic wall can thus be pressed' against the inner surface of the tubular stripping roller. Since the stripping roller is driven solely by friction, it is stopped practically instantaneously as two bodies contact each other over a large surface area. By suitable control of the pressure medium, the time for which the stripping roller is to remain stationary can be selectively varied, it being thus possible to adapt the operation to the properties of the sliver material. We have found that it is now possible to obtain surprising results with the clearer or stripper according to the invention where filamentary material such as synthetic thread, or staple-fiber thread or thread of poor-quality cotton is spun. The problem of the automatic cleaning of spinning frames in which material of this kind is processed has hitherto been assumed to beinsoluble in view of the susceptibility of the known installations to trouble.

The invention is diagrammatically illustrated by way of example in the accompanying drawing in which:

FIG. 1 is a side elevation of a pair of drawing rolls with a stripping roller;

FIG. 2 is a longitudinal section through the stripping roller shown in FIG. 1; and

FIG. 3 shows a corresponding fragmentary longitudinal section through the stripping roller in the braked condition.

FIG. 1 shows diagrammatically, by way of example, one embodiment in which a stripping roller 3 is provided in the zone of a grooved transport roller 2 coacting with a pressure roller 2a to convey a sliver 5. The stripping roller 3 is enclosed by a suction trough 4 connected to a suction duct 7. It is the purpose of the stripping roller 3 to remove flock or other dirt from the grooved roller 2 and to feed it to the zone of the suction trough 4 where the flock 8 then adhering to the surface of the stripping roller 3 is sucked off. Broken sliver may be sucked off through an entrance port 6 into the suction trough 4. The stripping roller 3 contains a brake (not shown in FIG. 1) by which this roller is intermittently stopped or by which the rotation thereof is retarded, to produce a temporary state of friction between the stripping roller 3 and the grooved roller 2. As soon as the braking action is terminated, the stripping roller 3 is again driven by the grooved roller 2 by frictional entrainment.

FIGS. 2 and 3 show by way of example one advantageous construction of a brake of this kind provided in the interior of the stripping roller 3. In this construction, the stripping roller 3 comprises a fixed shaft and, mounted thereon, a rotatable tube 9 sheathed in a leather cover 19. The leather cover 19 extends over a pair of end disks forming hubs in which the shaft 10 is secured in position as well as held against rotation. The rotatable tube 9 is mounted on the shaft 10 by means of bearings 21. The hubs 20 are surrounded by the leather cover 19 only for sealing purposes, no fixed connection existing at this location between the hubs and the tube 9.

A brake 11 in the form of an inflatable cylinder is provided in the interior of the tube 9. Mounted on the shaft 10 in axially spaced relationship are two collars or guide members 12 to which an elastic jacket or sleeve 13, for example a rubber hose, is secured. A spacing element 14 extends between the collars 12, this spacer consisting, for example, of a sleeve mounted on the shaft 10 or connected to these collars by means of hubs. The diameter of the cylindrical surface of the spacing element 14 is such as to leave a narrow annular pressure space 15 between the elastic jacket 13 and the spacing element 14, this space being in communication with a pressure source through a radial bore 16, an axial bore 17 and a connecting fitting 18. The outer surface of the elastic jacket 13 is normally spaced by a small annular clearance 22 from the inner surface of the tube 9.

When compressed air is introduced into the annular pressure space 15, the elastic jacket 13 bulges out and a relatively large surface area thereof bears against the inner surface of the tube 9 with elimination of clearance 22 (FIG. 3). The tube 9 is instantaneously arrested by the frictional contact thus produced, since the elastic jacket 13 is supported by the stationary shaft 10 through the guide elements 12. During this stoppage, the stationary stripping roller strips the flock 8 off the grooved roller 2. By suitable adjustment of the period during which the stripping roller 3 is stationary, it is possible to adapt the operation to the conditions of automatic cleaning prevailing in the drawing frame 1. Thus, for example, when 'an only slightly shedding sliver is processed, the stripping roller is stationary for a short period and rotates for a longer period. With sliver 5 tending to strong abrasion and lint formation, however, the period during which the stripping roller is stationary will be extended and the period of its rotation will be shortened.

It will be appreciated that an adjustment to fit widely varying operating conditions may be obtained by suitable control of the pressure medium. For this purpose, a control valve (not shown) will be used by which the connection between the pressure source and the pressure space 15 is interrupted. Tests carried out with the system described have shown that the frictional contact between the elastic jacket 13 and the rotatable tube 9 is instantaneously interrupted when the control valve disconnects the pressure source from the clearance 15 and connects the latter with the ambient atmosphere. It is surprising that it is possible to obtain with the system embodying an invention a sudden stopping of the stripping roller and an equally sudden rotation thereof without the occurrence of uncontrollable slip phenomena.

The brake illustrated in FIGS. 2 and 3 is an advantageous construction given merely by way of example. The invention may be realized in various ways. Thus, for example, instead of providing a cylindrical elastic jacket, an inflatable bag may be provided which in its inflated condition is in frictional contact with suitable surfaces of the tubular stripping roller 9 which may, for example, also be of laminated construction. Mechanical, electric or electromagnetic couplings or brakes of known construction may also be provided in the interior of the stripping roller. A hydraulic pressure medium may be used, but modifications of this kind do not entail the advantages afforded by the construction illustrated in the drawing and described by way of example, namely that the stripping roller is stopped with low inertia and little of energy without the occurrence of dynamic forces.

We claim:

1. In a system for conveying filamentary material with the aid of a pair of coacting transport rollers, the combination therewith of fixed mounting means including a shaft, a stripper roller frictionally engaging one of said transport rollers for cleaning the surface thereof, said stripper roller including a tube rotatably joumaled on said shaft, and brake means on said mounting means inside said stripper roller engageable therewith from within, said brake means comprising a body on said shaft with an elastically deformable wall portion and being externally operable for arresting said stripper roller against frictional entrainment by the engaged transport roller by expanding said deformable wall portion into contact with the inner wall of said tube.

2. The combination defined in claim 1 wherein said body is inflatable by a fluid under pressure, said mounting means forming a passage for the admission of said fluid to said body.

communicating with said passage.

5. The combination defined. in claim 4 wherein said passage includes an axial bore in said shaft and a radial bore in said spacer.

6. The combination defined in claim 1, further comprising suction means adjacent said stripper roller for removing adhering matter therefrom. 

1. In a system for conveying filamentary material with the aid of a pair of coacting transport rollers, the combination therewith of fixed mounting means including a shaft, a stripper roller frictionally engaging one of said transport rollers for cleaning the surface thereof, said stripper roller including a tube rotatably journaled on said shaft, and brake means on said mounting means inside said stripper roller engageable therewith from within, said brake means comprising a body on said shaft with an elastically deformable wall portion and being externally operable for arresting said stripper roller against frictional entrainment by the engaged transport roller by expanding said deformable wall portion into contact with the inner wall of said tube.
 2. The combination defined in claim 1 wherein said body is inflatable by a fluid under pressure, said mounting means forming a passage for the admission of said fluid to said body.
 3. The combination defined in claim 2 wherein said mounting means further includes a pair of axially spaced collars on said shaft, said body being a sleeve spanning said collars and normally defining a small annular clearance with the inner wall of said tube.
 4. The combination defined in claim 3 wherein said mounting means further includes a cylindrical spacer surrounding said shaft between said collars, said spacer defining with said sleeve an annular pressure chamber communicating with said passage.
 5. The combination defined in claim 4 wherein said passage includes an axial bore in said shaft and a radial bore in said spacer.
 6. The combination defined in claim 1, further comprising suction means adjacent said stripper roller for removing adhering matter therefrom. 